In the wireless communication system, the coverage range of each base station is basically fixed, but the user equipment (UE) generally is moving, thus, the UE often requires to hand over among a plurality of base stations so as to ensure the continuity of signals of the UE.
The handover process in the prior art is that: a source base station selects one destination base station which is able to carry out handover according to measurement results for neighboring base stations reported by the UE, and sends a handover request to the destination base station. The destination base station allocates resources for the UE according to the handover request, and returns a response message to the source base station. The source base station indicates the UE to carry out the handover after receiving the response message. In this process, if the load of the destination base station approaches saturation already and is unable to allocate the resources for the UE according to the handover request, then the source base station is required to re-select the destination base station, which delays the handover of the UE and reduces the handover efficiency.
In order to solve that problem, the prior art provides another handover process, which comprises: the source base station selecting a plurality of suitable base stations according to the measurement results for the neighboring base stations reported by the UE, and sending the handover requests to suitable base station. The suitable base stations allocate resources for the UE according to the handover requests, and return the response messages to the source base station. The source base station selects one destination base station from a plurality of suitable base stations according to the resource situations allocated for the UE by various suitable base stations, and commands the UE to hand over to the destination base station. Although that method improves the handover efficiency, all the suitable base stations have to allocate the resources for the UE, however, the UE is only able to hand over to one destination base station, and the resources allocated by other suitable base stations are all wasted, thereby affecting the load of the whole network.